Campbell was a huge correspondent, writing legendary letters to his writers critiquing their stories and often inspiring them. Perry Chapdelaine has published two volumes of the John W. Campbell Letters composed of letters by Campbell.

His list of Hugo nominations and wins is impressive, especially considering that by far the most important part of his career happened before the Hugos were instituted: Under his editorship, Astounding was nominated for Best Professional Magazine from 1953 to 1972, winning in 1953-1957, 1961, 1962, 1964, and 1965. In addition, he won the Best Professional EditorRetro Hugo all three times it was awarded, for 1946, 1951, and 1954.

The Campbell Award is named after him. (It is for new writers, and reflects the enormous impact he had on the field through the discovery, development and encouragement of new writers.) There is also the John W. Campbell Memorial Award, which is different.